A flat aluminum brazed monolithic cooling apparatus can be used with highly conformal low thermal performance heat spreaders, such as a gap pad or gap filler material, to accommodate vertical height variations in semiconductors and individual variations in planarity with respect to the cooling apparatus surface. After the individual semiconductors are attached to an array, the semiconductor height variations can be mapped for the entire array in order to select custom heat spreaders for each semiconductor element. This solution, generally, is effective for planar arrays, but, generally, this solution is not effective for semiconductor arrays with various vertical height variations due to the inefficiency of the heat spreaders and the difficulties of accurately mapping and fitting the custom heat spreaders. Thus, a need exists in the art for a semiconductor cooling apparatus with the features as described herein.